MIS cross-connector

ABSTRACT

A system for implanting a bone fixation system including an implant head inserter associated with each hook member and positionable relative to one of the elongate members to engage the hook member with the elongate member; a preliminary locking instrument associated with each implant head inserter and configured to engage the respective elongate member and lock the position of the hook member and implant head inserter relative to the elongate member; a compressor assembly configured to engage the implant head inserters and compress them toward one another; a path creation tool configured to be extended through holes in the hook members to define a connector member path between the hook members; and a rod introduction instrument configured to support the connector member and direct it through the connector member path. Methods of implanting a bone fixation system are also provided.

CROSS REFERENCE TO RELATED APPLICATION

The present application is a continuation application of U.S. patentapplication Ser. No. 15/226,011, filed Aug. 2, 2016 (published as U.S.Patent Pub. No. 2017-0128101), which is a continuation-in-part of U.S.patent application Ser. No. 14/936,071, filed Nov. 9, 2015, now U.S.Pat. No. 10,335,205, the contents of all of which are incorporatedherein by reference in their entireties for all purposes.

FIELD OF THE DISCLOSURE

The present disclosure relates to bone fixation constructs that mayinclude a stabilization element, and, more particularly, to bonefixation constructs that may include a connector system that may becoupled to, for example, one or more elongate members.

BACKGROUND OF THE DISCLOSURE

Intervertebral discs are susceptible to a variety of weaknesses andabnormalities that can affect their ability to provide support andstructure. Many of the abnormalities may be the result of, for example,trauma, degenerative disc disease, or tumors, which can cause severepain or damage to the nervous system. Also, movement of the spinalcolumn may be significantly limited by such abnormalities. Knowntreatments of such abnormalities typically involve affixing screws orhooks to one or more vertebrae and connecting the screws or hooks to arod that is aligned with the longitudinal axis of the spinal column toimmobilize the spinal segments with respect to each other. Pedicle screwsystems are frequently used to provide spinal fixation.

A number of pedicle screw systems are known, which share commontechniques and principles of screw placement and rod attachment.Generally, bone screws are screwed into pedicles of vertebrae andcoupled to at least one elongated rod. The pedicles, which consist of astrong shell of cortical bone and a core of cancellous bone, aregenerally used for the bone screw sites because they provide a strongpoint of attachment to a spine and, thereby, the greatest resistanceagainst bone-metal junction failure. Known pedicle screw systemstypically include pedicle screws and rods to stabilize adjacent spinalsegments. Such systems may also include variable angled coupling caps(or heads) on the pedicle screws to allow for angular adjustment of thecoupling mechanism between the rod and screws. Since pedicle size andangulation varies throughout the spinal column, several different sizesand shapes of pedicle screws are used in these systems. These systemsare generally designed to provide stable and rigid structures to promotebone growth and fusion. The systems may include a pair of rods, plates,or other elongate members affixed to the pedicle screws along thelongitudinal axis of the spine.

The strength and stability of a multi-rod, plate, or other elongatemember assembly can be increased by intercoupling the elongate memberswith a cross connector that extends substantially horizontal to thelongitudinal axes of the elongate members, across the spine. Due to awide variety of factors, the elongate members are seldom geometricallyaligned in clinical applications. Furthermore, typical cross connectorsare inserted through either a fully open or mini-open procedure,resulting in resection of the spinal ligaments and bone. A minimallyinvasive connector system with at least some adjustability is neededthat can accommodate for variations in geometrical alignment whileminimizing damage to the supporting anatomical structures.

SUMMARY OF THE DISCLOSURE

The present disclosure is generally directed towards a bone fixationsystem or construct for implanting in bone, wherein the bone fixationsystem comprises a connector assembly to add additional stability to thesystem. The bone fixation system comprises: a plurality of bone fastenerassemblies that attach to bone; a pair of elongate members that attachto the plurality of bone fastener assemblies; a connector member thatcontacts the pair of elongate members; and a plurality of locking capsthat secure the connector member and the elongate members to theplurality of bone fastener assemblies, wherein at least one of theplurality of locking caps comprises a cap portion and a hook portion,where the cap portion is adapted to rotate while the hook portion isstationary.

At least one of the plurality of bone fastener assemblies may comprise:a bone fastener that attaches to bone; a coupler that connects to thebone fastener; and an extender that connects to the coupler. Theextender may comprise: a coupling portion that attaches to the coupler;and a blade portion that attaches to the coupling portion. The couplingportion may comprise a threading. The blade portion may comprise a pairof extender blades. The cap portion of the at least one of the pluralityof locking caps may comprise a threading that engages the threading inthe coupling portion. The hook portion of the at least one of theplurality of locking caps may comprise a receptacle that receives acontact portion of the connector member. The receptacle may include aninterface section that contacts the contact portion of the connectormember, and a tapered section that contacts the contact portion of theconnector member and allows adjustability of the connector member in thereceptacle.

The bone fixation system may further comprise a sleeve that guides theconnector member and said at least one of the plurality of locking capsduring installation of the bone fixation system.

A system for implanting a bone fixation system is also disclosed. Thesystem includes an implant head inserter associated with each hookmember and positionable relative to one of the elongate members toengage the hook member with the elongate member; a preliminary lockinginstrument associated with each implant head inserter and configured toengage the respective elongate member and lock the position of the hookmember and implant head inserter relative to the elongate member; acompressor assembly configured to engage the implant head inserters andcompress them toward one another; a path creation tool configured to beextended through holes in the hook members to define a connector memberpath between the hook members; and a rod introduction instrumentconfigured to support the connector member and direct it through theconnector member path. Methods of implanting a bone fixation system arealso provided.

Additional features, advantages, and embodiments of the disclosure maybe set forth or apparent from consideration of the detailed descriptionand drawings. Moreover, it is to be understood that both the foregoingsummary of the disclosure and the following detailed description areexemplary and intended to provide further explanation without limitingthe scope of the disclosure as claimed.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings, which are included to provide a furtherunderstanding of the disclosure, are incorporated in and constitute apart of this specification, illustrate embodiments of the disclosure andtogether with the detailed description serve to help explain theprinciples of the disclosure. No attempt is made to show structuraldetails of the disclosure in more detail than may be necessary for afundamental understanding of the disclosure and the various ways inwhich it may be practiced. In the drawings:

FIG. 1 shows an exemplary embodiment of a bone fixation construct,according to the principles of the disclosure;

FIG. 2 shows a detailed view of a portion A of the bone fixationconstruct in FIG. 1;

FIGS. 3A-3C show a perspective view, a side view and a bottom view,respectively, of an exemplary embodiment of a locking cap, according tothe principles of the disclosure;

FIGS. 3D-3E show a bottom view of the locking cap in FIGS. 3A-3C with aconnector member;

FIG. 4 shows the bone fixation construct of FIG. 1 during a process ofinstalling the connector member;

FIG. 5 shows a detailed perspective view of a portion of the bonefixation construct in FIG. 4 after insertion of the connector member;

FIG. 6 shows a detailed side view of the portion of the bone fixationconstruct in FIG. 4 after insertion of the connector member;

FIG. 7 shows a detailed front (or back) view of the portion of thefixation construct in FIG. 4 after insertion of the connector member;

FIG. 8 shows another exemplary embodiment of a bone fixation construct,according to the principles of the disclosure;

FIG. 9 shows an exemplary embodiment of a connector assembly, accordingto the principles of the disclosure;

FIG. 10 shows an exemplary embodiment of a hook member that may beincluded in the connector assembly of FIG. 9;

FIG. 11 shows yet another exemplary embodiment of a bone fixationconstruct, according to the principles of the disclosure;

FIG. 12 shows another exemplary embodiment of a connector assembly,according to the principles of the disclosure;

FIG. 13 shows an exemplary embodiment of a hook member that may beincluded in the connector assembly of FIG. 12;

FIGS. 14A-14D show yet another exemplary embodiment of a hook member,according to the principles of the disclosure;

FIGS. 15A-15D show an example of an implant head inserter that may beused with the hook member of FIGS. 14A-14D;

FIGS. 16-26 show yet another exemplary embodiment of a bone fixationconstruct during a process of installing the construct in bone;

FIGS. 27-43 show yet another exemplary embodiment of a bone fixationconstruct during a process of installing the construct in bone; and

FIGS. 44-67 show yet another exemplary embodiment of a bone fixationconstruct during a process of installing the construct in bone.

The present disclosure is further described in the detailed descriptionthat follows.

DETAILED DESCRIPTION OF THE DISCLOSURE

The disclosure and the various features and advantageous details thereofare explained more fully with reference to the non-limiting embodimentsand examples that are described and/or illustrated in the accompanyingdrawings and detailed in the following description. It should be notedthat the features illustrated in the drawings are not necessarily drawnto scale, and features of one embodiment may be employed with otherembodiments as the skilled artisan would recognize, even if notexplicitly stated herein. Descriptions of well-known components andprocessing techniques may be omitted so as to not unnecessarily obscurethe embodiments of the disclosure. The examples used herein are intendedmerely to facilitate an understanding of ways in which the disclosuremay be practiced and to further enable those of skill in the art topractice the embodiments of the disclosure. Accordingly, the examplesand embodiments herein should not be construed as limiting the scope ofthe disclosure. Moreover, it is noted that like reference numeralsrepresent similar parts throughout the views of the drawings.

FIG. 1 shows an example of a bone fixation construct 10 that isconstructed according to the principles of the disclosure. The bonefixation construct 10 includes a plurality of bone fasteners 20 (forexample, four), one or more elongate members 30 (for example, two), aplurality of couplers 40 (for example, four), a plurality of extenders60 (for example, four), and a connector assembly 70. The variouscomponents of the bone fixation construct 10 (or 10A, or 10B, or 10C,discussed below) may be made of a material such as, for example,stainless steel, titanium, titanium-alloy, or the like.

FIG. 2 shows a detailed view of a portion A of the bone fixationconstruct 10 in FIG. 1, which includes the connector assembly 70. Asseen in the illustration, the connector assembly 70 includes a pair oflocking caps 210 and a connector member 35.

Referring to FIGS. 1 and 2, and referring to one of the bone fasteners20 with the understanding that the description may apply equally to theother bone fasteners 20, the bone fastener 20 may include a bone screw,such as, for example, any of the various pedicle screws common in theart, including, for example, a polyaxial pedicle screw. The bonefastener 20 may include a shaft portion that may be configured at thedistal end to penetrate and facilitate insertion of the bone fastener 20into bone. At the proximal end, the bone fastener 20 may include a headportion (not shown) that may be coupled to a corresponding coupler 40and configured to be, for example, polyaxially adjustable with respectto the corresponding coupler 40. For instance, the coupler 40 may pivotand/or rotate with respect to the corresponding bone fastener 20.

The head portion of the bone fastener 20 may include a tool receptacle(not shown) at its proximal end that is configured to receive a drivertool (not shown) to drive the bone fastener 20 into bone. The toolreceptacle may have a hexagon shape, a torque-screw shape, or any othershape that may facilitate the bone fastener 20 being driven into a boneby the driver tool.

The shaft portion of the bone fastener 20 may have a thread (not shown)that is adapted to be screwed into a bone, such as, for example, avertebra. Alternative formations may be formed in/on the shaft portionwhich provide the intended purposes of securing the bone fastener 20within a bone, as described herein. The shaft may have a tapered shape,which may be provided with a high pitch thread. It is noted that thelength, diameter, thread pitch, and thread diameter ratio of the shaftmay be selected based on the particular application of the bone fastener20, as understood by those skilled in the art.

The bone fasteners 20 may be substantially the same or substantiallydifferent from each other with respect to, for example, shaft length,shaft diameter, thread pitch, thread diameter ratio, and the like.

The elongate member 30 may include, for example, an elongate rod, a pin(not shown), a brace (not shown), a spring (not shown), a cord (notshown), a resilient extension (not shown), or any other stabilizationdevice that may be secured by the locking cap(s) 210 in the coupler(s)40 to provide stabilization to the construct 10. The locking cap(s) 210may be used to secure the elongate member 30 in the coupler(s) 40, asillustrated in FIG. 1.

Referring to one of the couplers 40, with the understanding that thedescription may apply equally to the other couplers 40, the coupler 40may include a coupler body 41 that may have, for example, a “tulip”shape (shown in FIG. 7). The coupler body 41 may be configured to rotateand/or pivot with respect to the bone fastener 20. At its proximal end,the coupler body 41 may include a pair of upwardly extending arms 42, 43and a slot 44 formed between the extending arms 42, 43 (for example,shown in FIG. 7). The slot 44 may be configured to receive the elongatemember 30, as illustrated in FIG. 7. The coupler body 41 may beconfigured to receive and hold the locking cap 210, as seen in FIG. 1.

The coupler body 41 may hold the locking cap 210 in a predeterminedlocation along the longitudinal axis of the coupler body 41 afterinsertion in the coupler body 41, so that a contact surface 216 (shownin FIG. 3B) of the locking cap 210 contacts and presses upon a surfaceof the elongate member 30 to hold and secure the elongate member 30 in afixed position, preventing the elongate member 30 from movingrotationally, angularly or longitudinally.

The coupler body 41 may include a threading that may be provided on theinterior surfaces of the upwardly extending arms 42, 43, as seen inFIG. 1. The threading may be configured to receive and engage acorresponding threading 212 on the locking cap 210 (shown in FIG. 3B).Alternatively, the coupler body 41 may include a tongue and grovemechanism (not shown), or any other retaining mechanism that can securethe locking cap 30 in a predetermined location in the coupler body 41.

Referring to FIG. 7, the upwardly extending arms 42, 43 of the couplerbody 41 may extend longitudinally in a superior direction and include aninterior, an exterior, and upper surfaces. One or both of the extendingarms 42, 43 may include one or more extender engaging portions (notshown), which may be configured to receive and engage correspondingportions of the extender 60. The coupler body 41 may be configured toreceive and engage a driver tool (not shown) and be driven by the toolto rotate and/or angularly adjust the coupler body 41. The coupler body41 may be adjusted (for example, rotated and/or pivoted) simultaneouslywith the corresponding extender 60. The extender 60 may be configured tobe attachable to and/or removable from the coupler body 41. The extender60 may be integrally formed with the coupler body 41 and configured tobe removable from the coupler body 41.

Referring to one of the extenders 60, with the understanding that thedescription may apply equally to the other extenders 60, the extender 60may include, for example, a coupling portion 64 and a blade portion 66.The blade portion may include a pair of extender blades 67, 68. Thelength and/or diameter of the extender 60 may vary to meet varyingpatient anatomy. The blade portion 66 may be coupled to, or integrallyformed with the coupling portion 64. The coupling portion 64 may includea threading 62 (shown in FIG. 2) that may be configured to receive andengage the threading 212 on the locking cap 210 (shown in FIG. 3B). Thecoupling portion 64 may be removably connected to a correspondingcoupler 40. The interface between the coupling portion 64 and thecorresponding coupler 40 may be configured to be substantially seamless,allowing the locking cap 210 to be seamlessly screwed longitudinallyalong the inner surfaces of the coupling portion 64 and the threading inthe coupler body 41.

The extender 60 may be configured to retract tissue and provide anunobstructed channel for insertion of tools (not shown), such as, forexample, a screw driver (not shown), rod introduction instrument 530(shown in FIGS. 24-25), and the like. For instance, the blade portion66, including the extender blades 67, 68, may be configured to provide alongitudinal channel that extends from the proximal ends of the extenderblades 67, 68, to the head portion (not shown) of the bone fastener 20,allowing for tools, such as, for example, the screw driver (not shown)to be inserted into, engage the head portion (not shown) and drive thebone fastener 20 into bone (not shown). The extender channel may beconfigured to receive and guide, for example, the elongate member 30,which may be introduced at the proximal end of the extender blades 67,68 and travel through the extender channel (for example, percutaneously)to the distal end of the blade portion 66. At the distal end of theblade portion 66, the elongate member 30 may be manipulated andmaneuvered using, for example, the rod introduction instrument 530(shown in FIGS. 24-25) into a desired position in the bone fixationconstruct 10 (shown in FIG. 1).

FIGS. 3A-3C show a perspective view, a side view and a bottom view,respectively, of an exemplary embodiment of the locking cap 210; andFIGS. 3D-3E show a bottom view of the locking cap 210 with a connectormember 35 adjustably positioned at different angles with respect to thelocking cap 210. As seen in FIGS. 1-2 and 3A-3E, the connector assembly70 may include the pair of locking caps 210 and the connector member 35.

Referring to FIGS. 1-2 and 3A-3C, each of the locking caps 210 may bepositioned in a corresponding coupler 40 and adjusted to secure acontact portion 355 of the connector member 35 in the bone fixationconstruct 10. Each locking cap 210 may include a cap portion 211 and ahook portion 213. The cap portion 211 may be attached to the hookportion 213 such that the cap portion 211 may be capable of spinningfreely with respect to the hook portion 213. The cap portion 211 mayinclude the threading 212 and a tool receptacle 215. The tool receptacle215 may have a hexagon shape, a torque-screw shape, or any other shapethat may facilitate the cap portion 211 being driven to, for example,rotate in and fasten to the coupler body 41 by the driver tool (notshown).

As seen in FIGS. 3A-3C, the hook portion 213 may include a receptacle214 that may be configured to receive a portion (for example, thecontact portion 355) of the connector member 35. The receptacle 214 mayinclude an interface section 217 and one or more tapered sections 218,219. The interface section 217 has an inner diameter this is greaterthan the outer diameter of the portion of the connector member 35 to besecured by the locking cap 210. The tapered sections 218, 219 may have aconical shape. The tapered sections 218, 219 have varying innerdiameters that range from a diameter that is substantially equal to theinner diameter of the interface section 217 nearest the interface andincreasing to an inner diameter that is greater than the inner diameterof the interface section 217, so as to allow angular movement of thecontact portion 355 of the connector member 35 in the receptacle 214,and, thereby, adjustability of the connector member 35 with respect tothe locking cap 210. The receptacle 214 may have a height H (shown inFIG. 3B) that is less than the height (or thickness) of, for example,the contact portion 355, such that a part of the contact portion 355,when the connector member 35 is installed in the receptacle 214, extendsbelow the lower surface of the hook portion 213, so that it may beforced by the hook portion 213 to contact and engage the surface of theelongate member 30, thereby securing the connector member 35, elongatemember 30 and locking cap 210 to the coupler 40.

Referring to FIGS. 3D-3E, the connector member 35 may be substantiallythe same as, or different from the elongate member 30. The connectormember 35 may be substantially round in its cross-section andsubstantially elongated in its length. The connector member 35 mayinclude, for example, an elongate rod (shown in FIG. 2), a pin (notshown), a brace (not shown), a spring (not shown), a cord (not shown), aresilient extension (not shown), or any other stabilization device thatmay be secured by the locking caps 210 to the construct 10. Theconnector member 35 may include attributes that may be selected basedon, for example, variations in anatomy. For instance, the connectormember 35 attributes that may be selected include a length, width,configuration, shape, or the like, depending on the particularapplication.

The connector member 35 may include the contact portion 355 at one orboth ends. The contact portion 355 may be formed between ends 354, 356,as seen in FIG. 3D. The contact portion 355 may be substantially flat,or it may be shaped to match to and receive the outer surface of theelongate member 30. For instance, the contact portion 355 may include aninterface portion similar to interface section 217 (shown in FIG. 3C)and/or at least one tapered portion similar to tapered section(s) 218(and/or 219). The contact portion 355 may be configured to providegreater surface contact between the surface(s) of the contact portion355 and the surface of the elongate member 30, thereby preventing theelongate member 30 from moving (for example, sliding, rotating, orpivoting). The contact portion 355 may have any structure that mayfacilitate engaging and securing the connector member 35 on top of theelongate member(s) 30, without departing from the scope or spirit of thedisclosure. The contact portion 355 may be configured to rest atop ofthe elongate member 30, as seen in FIG. 2.

The connector member 35 includes an end 352 that may include a toolengagement portion 353. The tool engagement portion 353 may beconfigured to be securely held by the rod introduction instrument 530(shown in FIGS. 24-25), such that the connector member 35 may be rotatedabout its longitudinal axis, and linearly and/or angularly adjusted inthe real-world coordinate system, including the x-axis, y-axis, andz-axis (shown in FIG. 5).

FIG. 4 shows the bone fixation construct 10 in a near-complete formduring a process of installing the connector member 35; and, FIGS. 5-8show detailed views of a portion B of the bone fixation construct 10after installation of the connector member 35 in the bone fixationconstruct 10.

Referring to FIG. 4, after a surgical area is cleaned on a patient, aminimally invasive incision made, muscle tissue moved to the side(s),and other common surgical procedures carried out, tracks for the bonefasteners 20 may be prepared. In this regard, hard bone surface may beremoved and a guide track may be inserted under x-ray guidance into, forexample, the pedicle of the vertebrae. The depth and position of theguide track may be checked. Where the bone fastener 20 includes a bonescrew, a thread may be tapped into the bone to form a tap (not shown) toreceive and securely hold the bone fastener 20. The process would berepeated for each bone fastener 20 of the bone fixation construct 10.

Using a driver tool (not shown), as is known by those skilled in theart, the driver tool may be inserted in and moved through the extenderchannel of the extender 60 toward the bone fastener 20. The tool maycontact the head portion (not shown) of the bone fastener 20 and thedriver tool may be manipulated until the driver tool head (not shown) issufficiently seated in and engaged with the tool receptacle (not shown)in the bone fastener 20 to ensure a secure connection. The driver tool,including the bone fastener assembly that comprises the bone fastener20, the coupler 40, and the extender 60, can then be aligned with thetap (not shown) in the bone and screwed into the threaded tap.

Alternatively, the bone fastener assembly, including the bone fastener20, the coupler 40, and the extender 60, may be partially installed inthe tap before being contacted by the driver tool. Once the bonefastener assembly is implanted in the desired position, the driver toolmay be removed and the process repeated for each bone fastener assembly,including the bone fastener 20, coupler 40, and extender 60 of the bonefixation construct 10.

After the bone fasteners 20 are securely and properly placed incorresponding taps, a first elongate member 30 may be inserted into andmoved through the extender channel of the extender 60 toward the distalend of the coupling portion 64 of the extender 60. The elongate member30 may be positioned in the slots 44 (shown in FIG. 7) of the pair ofadjacent couplers 40. The pair of couplers 40 may be adjusted andpositioned such that the slots 44 of the couplers substantially line upwith each other, providing a virtual channel for the elongate member 30.Once the elongate member 30 is seated in a desired position with respectto the pair of couplers 40, a cap (not shown) may be installed in thecoupler 40 proximate the distal end 301 of the elongate member 30 (shownin FIG. 4) and positioned to secure a portion of the elongate member 30in the coupler 40. In the case where cap (not shown) includes athreading, the cap may be screwed into the coupler 40 using a screwdriver (not shown).

Alternatively, the cap (not shown) may be partially installed in thecoupler 40 prior to installation of the bone fastener assembly, whichincludes the bone fastener 20, coupler 40, and extender 60. The distalend 301 of the elongate member 30 may be inserted through the opening inthe coupler 40 formed by the slot 44 and bottom side of the cap (notshown). After the elongate member 30 is seated in a desired position,the cap (not shown) may be positioned to secure the distal end 301 ofthe elongate member 30 in the coupler 40, such as, for example, byscrewing the cap (not shown) in the coupler 40.

The process may be repeated for the second elongate member 30, which maybe positioned in the slots 44 (shown in FIG. 7) of a second pair ofadjacent couplers 40. The second pair of couplers 40 may be adjusted andpositioned such that the slots 44 of the second pair of couplerssubstantially line up with each other, providing a virtual channel forthe second elongate member 30. Another cap (not shown) may be installedin the coupler 40 that is located proximate the distal end 301 of theelongate member 30 (shown in FIG. 4), and positioned to secure end 301in the coupler 40.

The cap(s) (not shown) may include the locking cap 210 (shown in FIGS.3A-3E), a cap 50 (shown in FIG. 8), a cap 92 (shown in FIG. 12), or anyother cap that is known in the art and that may be installed in thecoupler 40 to secure the elongate member 30 in the coupler, including,for example, a set screw, or the like, or any of the various caps thatinclude a bottom portion (not shown) that may be shaped to match theshape of the elongate member 30 so as to provide increased surfacecontact between the cap (not shown) and elongate member 30.

As seen in FIG. 4, after the pair of elongate members 30 are positionedin the bone fixation construct 10, a sleeve 300 may be positioned over aproximate end of the extender 60 and slid over the extender body towardits distal end. The sleeve 300 may be slid over part of the length ofthe extender 60, leaving sufficient space at its distal end to introduceand install the connector member 35 (shown in FIG. 5). Once theconnector member 35 is in position, the locking cap(s) 210 may beinserted into the corresponding coupler(s) 40.

Alternatively, one of the locking caps 210 may be installed prior toinstallation of the connector member 35. In this instance, an end of theconnector member 35 may be inserted through an opening 47 that is formedby the receptacle 214 (shown in FIG. 3A) and the elongate member 30, asseen in FIG. 4.

Referring to FIGS. 4-6, the sleeve 300 includes a sleeve body 310 thatmay have a longitudinal extender channel 320 formed therein andextending from (and through) the proximal end of the sleeve body 310 to(and through) the distal end of the sleeve body 310. The extenderchannel 320 may have an internal geometry (not shown) that prevents itfrom spinning around the extender 60. The extender channel 320 isconfigured to receive and slide on the extender 60, having an innerdiameter that is greater than the outer diameter of the extender 60.

The sleeve body 310 may also include an instrumentation channel 330formed therein. The instrumentation channel 330 extends from (andthrough) the proximal end of the sleeve body 310 to (and through) thedistal end of the sleeve body 310. The instrumentation channel 330 mayhave an internal geometry (not shown) that guides the connector member35 to and through a sleeve opening 340 formed in the distal end of thesleeve 300. The sleeve opening 340 may be formed on one side of thesleeve body 310, allowing for exit of the connector member 35 on thatside of the sleeve body 310; or, the sleeve opening 340 may be formedas, for example, a cut-out in the distal end of the sleeve body 310,allowing for exit of the connector member 35 on either side of thesleeve body 310.

The sleeve 310 may include a sleeve cutout 350 at its distal end thatmay be contoured to match the shape of the elongate member 30. Thesleeve cutout 350 may facilitate proper alignment of the sleeve 310 withthe elongate member 30, as well as help to keep the sleeve 310stationary with respect to the elongate member 30.

The extender channel 320 and the instrumentation channel 330 may beconfigured such that the locking cap 210 may be inserted in the proximalend of the sleeve body 310 and moved through the channels 320, 330 toand through the distal end of the sleeve body 310, and to thecorresponding coupler 40. The inner diameter (or width) of theinstrumentation channel 330 may be less than the inner diameter (orwidth) of the extender channel. The instrumentation channel 330 mayinclude an inner geometry that may help to align and position the hookportion 213 of the locking cap 210 (shown in FIG. 3A) such that thelongitudinal axis of the locking cap 210 is substantially parallel tothe elongate member 30 in the corresponding coupler 40.

Referring to FIGS. 5-6, the bone fixation construct 10 may be secured bythreading the locking caps 210 into locked positions. In this regard, aseach of the locking caps 210 is threaded (or screwed) in thecorresponding coupler 40, the locking cap 210 travels toward theelongate member 30, locking the elongate member 30 in place andsimultaneously locking the connector member 35 on top of the elongatemember 30.

Referring to FIG. 7, the connector member 35 may be positioned such thatthe contact portion 355 is positioned on top of the elongate member 30.The ends 354, 356 may assist in positioning the contact portion 355 ontop of the elongate member 30, as well as properly positioning theconnector member 35 in the connector assembly 70. The ends 354, 356 mayfunction as stops to prevent the connector member 35 from moving beyondeither end 354, 356 with respect to the elongate member 30. Theconnector member 35 may include a contact portion 355 (not shown) at itsother end (not shown), which may be similarly seated on top of andsecured to the second elongate member 30.

At completion of placement of the bone fixation construct 10, theconstruct may be installed in adjacent vertebrae, with the bonefasteners 20 implanted in the pedicles of the vertebrae. FIG. 26 showsan example of a bone fixation construct 10C installed in adjacentvertebrae, which is discussed in greater detail below. The connectormember 35 (secured with locking caps 210) connects and secures theadjacent elongate members 30 to each other, thereby providing rigidityand stabilization between the elongate members 30.

FIG. 8 shows another exemplary embodiment of a bone fixation construct10A, according to the principles of the disclosure. The bone fixationconstruct 10A includes a plurality of the bone fasteners 20, a pluralityof couplers 40A, a plurality of caps 50, and a connector assembly 70A.Each of the caps 50 may include a driver receptacle 55 that receives andis engaged by a driver (not shown) to rotate and, thereby, travel towardthe elongate member 30 seated in the coupler 40A, contacting andsecuring the elongate member 30 in the coupler 40A. The contact surface(not shown) of the caps 50 may be shaped to substantially match theouter shape of the elongate member 30, thereby increasing the surfacecontact and coefficient of static friction between the elongate member30 and bottom surface of the caps 50.

The bone fixation construct 10A may be installed according to a processsimilar to that described above with respect to the bone fixationconstruct 10, or any other process commonly used to implant constructs,as understood by those skilled in the art. Once the bone fixationconstruct 10 is installed, the connector assembly 70A may be installed,as described herein, thereby providing increased stability of theconstruct.

FIG. 9 shows an exemplary embodiment of the connector assembly 70A,which provides a low profile configuration that can be inserted througha minimally invasive surgery (MIS) opening, and which may easily attachto pre-existing elongate members. The connector assembly 70A includes aconnector member 80 and a pair of hook members 90. The connector member80 may be similar to the connector member 35 (shown in FIG. 1) or theelongate member 30. The connector member 80 may include, for example, anelongate rod (shown in FIG. 9), a pin (not shown), a brace (not shown),a spring (not shown), a cord (not shown), a resilient extension (notshown), or any other stabilization device that may be secured in thehook members 90 to provide stabilization. The connector member 80 mayinclude attributes that may be selected based on, for example,variations in anatomy. For instance, the connector member 80 attributesmay be selected from various lengths, widths, shapes, or the like,depending on the particular application.

The connector member 80 may be secured at each end 82, 84 to the hookmembers 90 by means of fasteners 92. Each fastener 92 may include arecess 94 that receives and is engaged by a driver tool (not shown) todrive the fastener 92 in and toward the connector member 80, therebycontacting and securing the connector member 80 to the hook member 90.The fastener 92 may include a threading 99 (shown in FIG. 12). Thefastener 92 may include, for example, a set screw, a bolt, a screw, acap, a pin, or the like.

FIG. 10 shows an exemplary embodiment of the hook member 90. As seen,the hook member 90 includes a hook member body 91 that may include anopening 93, a receptacle 95, a hook portion 96, and an opening 97. Theopening 93 may be configured to receive and engage the fastener 92. Theopening 93 may include a threading that may engage the correspondingthreading 99 on the fastener 92 and cause the fastener 92 to be screweddownward (or upward) when the fastener 92 is rotated with respect to thehook member body 91.

The receptacle 95 may be shaped to receive and securely hold theelongate member 30 (shown in FIG. 8) in the hook member body 91. Thereceptacle 95 may be configured to catch and hold the entirety of thewidth (or diameter) of the elongate member 30 in the hook member body91.

The hook portion 96 forms a lower part of the receptacle 95. The hookportion 96 may be shaped to catch and aid in attaching and securing thehook member 90 to the elongate member 30. For instance, the hook portion96 may include an upwardly inclined configuration to catch the elongatemember 30, such that the hook member body 91 will move upward withrespect to the elongate member 30 as the elongate member 30 is moveddeeper into the receptacle 95.

The opening 97 may be shaped to substantially match the shape of the end82 (or 84) of the connector member 80. In the example seen in FIGS.8-10, the opening 97 has a round shape, which receives and holds acylindrically-shaped end 82 (or 84) of the connector member 80. Theinner diameter of the opening 97 is greater than the outer diameter ofthe connector member end 82 (or 84). The inner diameter of the opening97 extends into the receptacle 95 (shown in FIG. 10), such that when theelongate member 30 is properly seated in the receptacle 95 and the end82 (or 84) of the connector member 80 is inserted into the opening 97,the connector member 80 may contact and force the elongate member 30toward the hook portion 96 and inward toward the connector member body91. The connector member 80 may be forced against the elongate member 30by operation of the fastener 92, which contacts the connector member 80and forces the connector member 80 against the elongate member 30 as thefastener 92 is screwed into the connector member body 91.

The opening 97 may include internal geometry such that it guides theconnector member 80 toward the hook portion 96 as the connector memberend 82 (or 84) is inserted further into the opening 97. For instance,the interior surface of the opening 97 may be angled so that thesurfaces of inner walls of the opening 97 force the connector member 80downward as the end 82 (or 84) travels deeper into the opening 97.

Referring to FIGS. 9-10, after the bone fixation construct 10A isimplanted, the connector assembly 70A may be installed in the construct.According to a non-limiting example of an installation process, one ofthe hook members 90 may be delivered to the site of the constructthrough a minimally invasive surgical opening, positioned proximate apredetermined portion of one of the elongate members 30, and hooked ontothe elongate member 30 using a tool (not shown) that may be similar to,for example, the implant head inserter 400 (shown in FIGS. 15A-15D),such that the elongate member 30 is positioned completely within thereceptacle 95. Using the same tool (not shown) or another tool (notshown) the connector member 80 may be delivered to the installation siteof the hook member 90 and the end 82 (or 84) may be inserted into theopening 97 in the hook member 90. The fastener 92 may be rotated using,for example, a screw driver (not shown) to drive the fastener 92 towardthe hook portion 96, thereby contacting and forcing the connector member80 against the elongate member 30 and forcing the elongate memberdownward and inward in the hook member body 91, against the inner andlower surfaces of the receptacle 95. As illustrated, the hook portion 96may be shaped so as to prevent removal of the elongate body 30 from thehook member body 91 without first releasing the fastener 92 and/orremoving the connector member 80.

The second hook member 90 may be delivered to the site of the connectorassembly 70A and attached to the end 84 (or 82) of the connector member80 (via opening 97 in the hook member 90) substantially simultaneouslywith attachment to the second elongate member 30 (via receptacle 95).Alternatively, the second hook member 90 may be attached to the secondelongate member 30 and rotated about the elongate member to receive andinsert the connector member 80 into the opening 97 of the second hookmember 90. Once installed in the desired position, the second fastener92 may be tightened to securely lock the connector member 80 andelongate member 30 in the hook member 90.

FIG. 11 shows yet another exemplary embodiment of a bone fixationconstruct 10B. The bone fixation construct 10B may include substantiallythe same elements as the bone fixation construct 10A (shown in FIG. 9),except that the construct 10B includes a connector assembly 70B in lieuof the connector assembly 70A.

FIG. 12 shows a perspective view of the connector assembly 70B that maybe introduced to the bone fixation construct 10B through an MIS openingto add stability to the construct, while minimizing damage to supportinganatomical structures. As seen in FIG. 12, the connector assembly 70B isa low profile structure that may easily attach to pre-existing elongatemembers.

FIG. 13 shows an example of a clip member 190 that may be included inthe connector assembly 70B.

Referring to FIGS. 11-13, the connector assembly 70B may include a pairof clip members 190, a pair of fasteners 92 and the connector member 80.The clip member(s) 190 may include a clip member body 191 and a clamp196. The clamp 196 may include, for example, a spring clamp housedwithin an external collet, such that when the clamp 196 is pushed ontoan elongate member 30, the external collet pushes on the spring forks,keeping the clip member 190 locked to the elongate member 30. The clipmember body 191 may include a pair of upwardly extending arms 192 and apair of downwardly extending arms 197, 198. The upwardly extending arms192 of the clip member body 191 may extend longitudinally in a superiordirection and include an interior, an exterior, and upper surfaces. Theinterior of the upwardly extending arms 192 may include a threading (notshown) and form an opening 193 to receive and engage a correspondingthreading on the cap 92. The arms 192 form a slot 199 therebetween thatis configured to receive and hold the connector member 80, asillustrated in FIGS. 11 and 12.

The downwardly extending arms 197, 198 may extend longitudinally in aninferior direction and include an interior, an exterior, and lowersurfaces. The interior of the downwardly extending arms 197, 198 mayinclude a receptacle (not shown) formed by inner walls of the clipmember body 191 and extending arms 197, 198. The receptacle (not shown)may include an opening in the superior direction, such that when theclamp 196 is installed therein, the connector member 80 may contact andpress upon the upper surface (not shown) of the clamp 196, therebyforcing the clamp 196 to compress and reduce the diameter of the openingbetween the extending arms 197, 198. In this regard, the interior of theclip member body 191 may be hollowed along its longitudinal axis,providing an unobstructed pass-through from the opening 193 and downwardthrough the slot 195.

The interior of the extending arms 197, 198 may include channels (notshown) or cut-outs (not shown) that are configured to receive and holdportions of the clamp 196. The arms 197, 198 form a slot 195therebetween that is configured to receive and hold the elongate member30, as illustrated in FIG. 11. The channels (not shown) or cut-outs (notshown) may be formed to have a gradient angle such that when the clamp196 is pressed (for example, by the connector member 80 under force ofthe cap 92), the side walls of the clamp 196 are forced inward by theinterior walls of the extending arms 197, 198, toward the center pointof the slot 195. The channel formed by the slot 195 may be substantiallyorthogonal to the channel formed by the slot 199.

Referring to FIGS. 11-12, after the bone fixation construct 10B isimplanted, the connector assembly 70B may be installed in the construct.According to a non-limiting example of an installation process, one ofthe clip members 190 (with the clamp 196) may be delivered through a MISopening to the site of the construct, positioned proximate apredetermined portion of one of the elongate members 30, and clippedonto the elongate member 30 using a tool (not shown), which may besimilar to the implant head inserter 400 (shown in FIGS. 15A-15D), suchthat the slot 195 is positioned on and envelopes the diameter of theelongate member 30. The process may be repeated for the second clipmember 190.

The fasteners 92 may be pre-installed in the clip members 190, andpositioned so as to form sufficient space in the slots 199 to allow theconnector member 80 to pass there-through and be installed in the clipmembers 190.

Once the clip members 190 are in place, using the same tool (not shown),or another tool (not shown), the connector member 80 may be delivered tothe installation site of the clip members 190 and the connector member80 may be passed through the slot 199 of one of the clip members 190 andpositioned with the end 82 (or 84) in the slot 199 of the other clipmember 190, as seen in FIG. 12. The fasteners 92 may be rotated using,for example, a screw driver (not shown) to drive the fastener 92 againstthe connector member 80, thereby forcing the connector member 80 againstthe upper surface (not shown) of the clamp 196, forcing the clamp 196 tocompress around and secure to the elongate member in the slot 195.

Alternatively, the connector assembly 70B may be preassembled with thefasteners 92 partially tightened so as to keep the connector assembly70B intact during insertion, delivery, positioning and mounting of theconnector assembly 70B to the elongate members 30, but sufficientlyloose to allow for manipulation of the connector member 80 and/orinstallation of the clip members 190 onto the corresponding elongatemembers 30. Once the connector assembly 10B is mounted and positioned inthe desired locations on the elongate members 30, the fasteners 92 maybe tightened and, thereby, the connector assembly 70B may be locked andsecured in the bone fixation construct 10B.

FIGS. 14A-14D show yet another exemplary embodiment of a hook member 290that may be included in a connector assembly 70C (shown in FIG. 18) of abone fixation construct 10C. FIG. 14A shows a front (or back) view ofthe hook member 290; FIG. 14B shows a back (or front) view of the hookmember 290; FIG. 14C shows a side view of the hook member 290; and, FIG.14D shows a perspective view of the hook member 290.

Referring to FIGS. 14A-14D, the hook member 290 comprises a hook memberbody that may include an opening 293, a receptacle 295, a hook portion296, and an opening 297. The hook member body may include a guide(s) 298that may facilitate alignment of the hook member during installation by,for example, the implant head inserter 400 (shown in FIGS. 15A-15D). Thehook member 290 may include a tool engagement portion 291 that may becontacted and engaged with, for example, the implant head inserter 400(shown in FIGS. 15A-15D) to assist the implant head inserter 400 tograsp and hold the hook member 290 during installation.

The opening 293 may be configured to receive and engage the fastener 92.The opening 293 may include, for example, a stab incision. The opening293 may include a threading that may engage a corresponding threading onthe fastener 92 and cause the fastener 92 to be screwed downward (orupward) when the fastener 92 is rotated with respect to the hook memberbody. The opening 293 may be formed by a pair of upwardly extending arms292.

The receptacle 295 may be shaped to receive and securely hold theelongate member 30 (shown in FIG. 18) in the hook member body. Thereceptacle 295 may be configured to catch and hold the entirety of thewidth (or diameter) of the elongate member 30 in the hook member body.The receptacle 295 may include one or more capture members 299 that helpto pre-lock and hold the elongate member 30 in the receptacle 295,preventing the hook member 290 from falling off once in place. The oneor more capture members 299 may provide a user with tactile feel oncethe elongate member 30 is secured in the receptacle 295.

The hook portion 296 forms a lower part of the receptacle 295, and maybe shaped to catch and aid in attaching and securing the hook member 290to the elongate member 30. For instance, the hook portion 296 mayinclude an upwardly inclined configuration to catch the elongate member30, such that the hook member body will move upward with respect to theelongate member 30 as the elongate member 30 is moved deeper into thereceptacle 295.

The opening 297 may be shaped to substantially match the shape of theconnector member 180 (shown in FIG. 18). As seen in FIGS. 14A and 14B,the opening 297 may have a round shape that receives and holds acylindrically-shaped connector member 180. The inner diameter of theopening 297 is greater than the outer diameter of the connector member180. The inner diameter of the opening 297 extends into the receptacle295, such that when the elongate member 30 is properly seated in thereceptacle 295 and the connector member 180 is inserted into the opening297, the connector member 180 may contact and force the elongate member30 toward the hook portion 296 (or bottom surface of the receptacle 295)and inward toward the connector member body under force of the fastener92. For instance, the connector member 180 may be forced against theelongate member 30 by operation of the fastener 92, which contacts theconnector member 180 and forces the connector member 180 against theelongate member 30 as the fastener 92 is screwed into the connectormember body.

The connector member 180 may be similar to the connector member 35(shown in FIG. 1), the elongate member 30 (shown in FIG. 1), theconnector member 80 (shown in FIG. 9), or the like. The connector member180 may include, for example, an elongate rod (shown in FIG. 18), a pin(not shown), a brace (not shown), a spring (not shown), a cord (notshown), a resilient extension (not shown), or any other stabilizationdevice that may be secured in the hook members 290 to providestabilization. The connector member 180 may include attributes that maybe selected based on, for example, variations in anatomy. For instance,the connector member 180 attributes may be selected from variouslengths, widths, shapes, or the like, depending on the particularapplication.

The opening 297 may include a geometry such that it guides the connectormember 180 toward the hook portion 296 as the end of the connectormember 180 is inserted further into the opening 297. For example, theinterior surface of the opening 297 may include tapered sections 294,which may be angled so that the surface of the tapered sections 294forces the connector member 180 toward the center and/or downward as theend of the connector member 180 travels deeper into the opening 297.

FIGS. 15A-15D show an example of an implant head inserter 400 that maybe used with the hook member 290 to install the hook member 290 in abone fixation construct 10C (shown in FIG. 18). FIG. 15A shows theimplant head inserter 400 in an unlocked position; FIG. 15B shows theimplant head inserter 400 in the unlocked position with a hook member290 attached at the distal end; FIG. 15C shows the implant head inserter400 in a locked position with the hook member 290 attached at the distalend; and, FIG. 15D shows another view of the implant head inserter 400in the locked position with the hook member 290 attached at the distalend.

Referring to FIG. 15A, the implant head inserter 400 may include ahandle 410, a sleeve 420, and an inner member 430. The inner member 430may include a spring clamp that may be compressed by the sleeve 420 asthe inner member 430 travels in the direction of the handle 410.Conversely, the sleeve 420 may release the inner member 430 as the innermember 430 travels in the direction away from the handle 410. The sleeve420 may include a functional gap (or cutout) 424 formed between a pairof extending members, as seen in FIG. 15A, which may be configured toflex outward or inward as the inner member 430 travels toward and awayfrom the handle 410.

The sleeve 420 may include a handle engagement portion (not shown) thatattaches to the handle 410, allowing the handle 410 to rotate about thelongitudinal axis of the sleeve 420. The handle 410 may be coupled tothe inner member 430 and configured to drive the inner member 430 as thehandle 410 is rotated. The sleeve may include one or more openings 422,which may show portions of the inner member 430.

The inner member 430 may include a substantially cylindrical body with apair of extending members 434, 436 at its distal end 433. The extendingmembers 434, 436 may be made of a memory-shape material (for example, ametal, a plastic, or the like, that is made to hold a predeterminedshape, but compress under force) whereby the extending members 434, 436expand away from each other as the distal end 433 moves out and awayfrom the distal end of the sleeve 420. Conversely, the extending members434, 436 compress toward each other as the distal end 433 moves into thesleeve 4320. The extending members 434, 436 may include a guide-contactportion (not shown) that contacts and engages the guide(s) 298 on thehook member 290 to properly align the hook member 290 duringinstallation.

Referring to FIGS. 15B and 15C, the implant head inserter 400 may beconfigured into the unlocked position by, for example, turning thehandle 401 in a predetermined direction, and a hook member 290 may beattached to the distal end 433 (shown in FIG. 15B). The implant headinserter 400 may then be operated to the locked position by, forexample, turning the handle 410 in the opposite direction, therebylocking the hook member 290 at its distal end (shown in FIG. 15C). FIG.15D shows another view of the implant head inserter 400 in the lockedposition with the hook member 290 attached at the distal end.

FIGS. 16-26 show yet another exemplary embodiment of a bone fixationconstruct 10C during a process of installing the construct in bone. Thebone fixation construct 10C may include substantially the same elementsas the bone fixation construct 10A (shown in FIG. 8) or 10B (shown inFIG. 11), except that the construct 10C includes a connector assembly70C in lieu of the connector assembly 70A or 70B, respectively. The bonefixation construct 10C may be installed according to a process similarto that described above with respect to the bone fixation construct 10(or 10A, or 10B), or any other process commonly used to implantconstructs, as understood by those skilled in the art. Once the bonefixation construct 10C is installed, the connector assembly 70C may beinstalled, as described herein, thereby providing increased stability ofthe construct.

Referring to FIGS. 16-18, after the bone fixation construct 10C isimplanted, the connector assembly 70C may be installed in the construct.According to a non-limiting example of an installation process, one ofthe hook members 290 may be delivered to the site of the constructthrough a minimally invasive surgical opening, positioned proximate apredetermined portion of one of the elongate members 30, and hooked ontothe elongate member 30 using the implant head inserter 400 (shown inFIG. 16), such that the elongate member 30 is positioned completelywithin the receptacle 295. Once the hook member 290 is properly hookedon to the elongate member 30, such as, for example, when the elongatemember 30 is within the receptacle 295 (shown in FIG. 14C) and caught bythe capture member(s) 299, the handle 410 may be operated to extend theinner member 430, thereby releasing the hook member 290 (shown in FIG.17).

FIG. 18 shows an example of inserting the fastener 92 into an innerchannel of the sleeve 420 and inner member 430, so as to deliver thefastener 92 to the hook member 290 and install the fastener 92 into thehook member 290, thereby securing the connector member 180 in the hookmember 290, and securing the connector member 180 and hook member 290 tothe elongate member 30.

FIGS. 19-26 show the various stages of installation of the connectorassembly 70C in the bone fixation construct 10C. Initially, using theimplant head inserter 400, a first hook member 290 may be attached toone of the elongate members 30 (shown in FIG. 19). The process may thenbe repeated for the second hook member 290, attaching it to the secondelongate member 30 (shown in FIG. 20). With both hook members 290attached to respective elongate members 30, the connector member 180 maybe installed in the hook members 290 using, for example, the rodintroduction instrument 530 to insert and position the connector member180 in the hook members 290 (shown in FIGS. 21 and 24-25). The connectormember 180 may include a frustoconical end which may facilitateintroduction of the connector member 180 through various tissueincluding ligaments and bone. For example, FIGS. 25 and 26 showconnector element 180 being passed through a spinous process of avertebra during installation. It is contemplated that this is achievedby making the end of the connector member 180 sharp enough to penetratetissue or to use a separate instrument to create an initial through borefor the connector member 180 to travel through during installation. Oncethe connector member 180 is properly positioned in the hook members 290,fasteners 92 may be installed in the hook members 290, thereby securingthe connector member 180 and hook members to the elongate members 30,and bone fixation construct 10C (shown in FIGS. 22-23 and 26).

FIG. 26 shows an example of the bone fixation construct 10C, includingconnector assembly 70C implanted in a pair of adjacent vertebrae 510 ofa spine 500, according to the principles of the disclosure. As seen, thebone fixation construct 10C provides a low profile structure withincreased stability.

Referring to FIGS. 27-43, another exemplary embodiment of a bonefixation construct 10D and an exemplary method of implanting suchconstruct according to the principles of the disclosure will bedescribed. With reference to FIGS. 27 and 30, the bone fixationconstruct 10D is similar to the previous embodiments and includes aplurality of the bone fasteners 20, a pair of elongate members 30, aplurality of couplers 40, 40A, a plurality of caps 50, and a connectorassembly 70D. In the illustrated embodiment, the bone fixation construct10D includes a pair of couplers 40 with an extender 60 similar to thosedescribed with respect to FIG. 1 and a pair of couplers 40A which do notinclude extenders. It is understood that any desired combination ofcouplers 40, 40A may be utilized in the bone fixation construct 10D.Each coupler 40, 40A is configured to receive one of the caps 50 whichcontacts and secures the elongate member 30 in the respective coupler40, 40A. The contact surface (not shown) of the caps 50 may be shaped tosubstantially match the outer shape of the elongate member 30, therebyincreasing the surface contact and coefficient of static frictionbetween the elongate member 30 and bottom surface of the caps 50.

The bone fasteners 20, elongate members 30, couplers 40, 40A, and caps50 may be installed according to a process similar to that describedabove or any other process commonly used to implant constructs, asunderstood by those skilled in the art. Once the bone fasteners 20,elongate members 30, couplers 40, 40A, and caps 50 are installed asillustrated in FIG. 28, the connector assembly 70D may be installed, asdescribed herein, thereby providing increased stability of theconstruct.

Referring to FIGS. 27, 30 and 32-34, the connector assembly 70D issimilar to the previous embodiment and includes a pair of hook members390 and a connector member 180. The connector member 180 is similar tothe previous embodiment and may include, for example, an elongate rod(shown in FIG. 27), a pin (not shown), a brace (not shown), a spring(not shown), a cord (not shown), a resilient extension (not shown), orany other stabilization device that may be secured in the hook members390 to provide stabilization. The connector member 180 may includeattributes that may be selected based on, for example, variations inanatomy. For instance, the connector member 180 attributes may beselected from various lengths, widths, shapes, or the like, depending onthe particular application. The connector member 180 may be secured ateach end 182, 184 to the hook members 390 by means of fasteners 92similar to those described above.

The hook members 390 are similar to the previous embodiment with eachhook member 390 comprising a hook member body including an opening 393formed between a pair of upwardly extending arms 392, a receptacle 395,a hook portion 396, and an opening 397. The primary distinction from thehook member 290 of the previous embodiment is that the hook member bodyof the present embodiment tapers to the upwardly extending arms 392, asseen in FIG. 33, such that the arms 392 are easily received in theimplant head inserter 400.

The opening 393 is configured to receive and engage the fastener 92. Theopening 393 may include, for example, a stab incision. The opening 393may include a threading that may engage a corresponding threading on thefastener 92 and cause the fastener 92 to be screwed downward (or upward)when the fastener 92 is rotated with respect to the hook member body.The receptacle 395 is shaped to receive and securely hold the elongatemember 30 in the hook member body as in the previous embodiments. Thehook portion 396 forms a lower part of the receptacle 395, and may beshaped to catch and aid in attaching and securing the hook member 390 tothe elongate member 30 as in the previous embodiments. The opening 397may be shaped to substantially match the shape of the connector member180, for example, the opening 397 may have a round shape that receivesand holds a cylindrically-shaped connector member 180. In at least oneembodiment, the inner diameter of the opening 397 is greater than theouter diameter of the connector member 180. The inner diameter of theopening 397 extends into the receptacle 395, such that when the elongatemember 30 is properly seated in the receptacle 395 and the connectormember 180 is inserted into the opening 397, the connector member 180may contact and force the elongate member 30 toward the hook portion 396and inward toward the connector member body under force of the fastener92. For instance, the connector member 180 may be forced against theelongate member 30 by operation of the fastener 92, which contacts theconnector member 180 and forces the connector member 180 against theelongate member 30 as the fastener 92 is screwed into the connectormember body.

The connector member 180 may be similar to the connector member 35(shown in FIG. 1), the elongate member 30 (shown in FIG. 1), theconnector member 80 (shown in FIG. 9), or the like. The connector member180 may include, for example, an elongate rod (shown in FIG. 27), a pin(not shown), a brace (not shown), a spring (not shown), a cord (notshown), a resilient extension (not shown), or any other stabilizationdevice that may be secured in the hook members 390 to providestabilization. The connector member 180 may include attributes that maybe selected based on, for example, variations in anatomy. For instance,the connector member 180 attributes may be selected from variouslengths, widths, shapes, or the like, depending on the particularapplication.

Referring to FIGS. 29-30, according to a non-limiting example of aninstallation process, each of the hook members 390 may be delivered tothe site of the construct through a MIS opening, positioned proximate apredetermined portion of one of the elongate members 30, and hooked ontothe elongate member 30 using the implant head inserter 400 (similar tothat shown in FIG. 16), such that the elongate member 30 is positionedcompletely within the receptacle 395. Once each of the hook members 390is properly hooked on to the elongate member 30, such as, for example,when the elongate member 30 is within the receptacle 395, a preliminarylocking instrument 600 is positioned relative to each implant headinserter 400 to temporarily maintain the position of the hook member 390and prevent disengagement thereof from the respective elongate member30.

Referring to FIGS. 31-34, in the present embodiment, each preliminarylocking instrument 600 includes a hollow locking sleeve 602 extendingfrom an open proximal end 610 to a distal end 620. The distal end 620 ofthe locking sleeve 602 includes a plurality of fingers 622circumferentially spaced from one another by a plurality of openings624. The locking sleeve 602 is configured to slide over the outersurface of the implant head inserter 400 such that the distal end 620may be advanced toward the hook member 390 as illustrated in FIGS. 33and 34. With the preliminary locking instrument 600 fully advanced, thedistal end 620 of the locking sleeve 602 extends about the hook memberarms 392 with fingers 622 extending on opposed sides of the elongatemember 30 and the elongate member 30 passing through two of the openings614. The fingers 612 may extend proximate the hook portion 396 such thatthe elongate member 30 is prevented from moving out of the receptacle395.

Turning to FIGS. 35-37, a compressor assembly 650 is positioned over thelocking sleeves 602. The compressor assembly 650 includes a first tube652 configured to slide over a first of the sleeves 602 and a secondtube 662 configured to slide over the other sleeve 602. The first tube652 is pivotally connected to a first body 654 via a pivot pin 653. Aslide bar 656 extends from the first body 654 such that the first tube652, the first body 654 and the slide bar 656 define a generally rightangle. The slide bar 658 includes a series of teeth 658 defined alongone edge thereof and configured to be engaged by a pivotal pawl 668associated with the second tube 662, as will be described in more detailhereinafter. In the illustrated embodiment, the slide bar 656 has ascale 659 along a surface thereof. The scale 659 may be used todetermine a desired size of the connector member 180.

The second tube 662 has a second body 664 extending therefrom. Thesecond body 664 includes a slide bar receiving portion 665 with athrough opening 666 extending therethrough. The slide bar receivingportion 665 extends parallel to the slide bar 656 which extends throughthe opening 666. A pawl 668 is pivotally connected to the second body664 and is biased such that a tip 669 of the pawl 668 is normally biasedinto engagement with the teeth 658 along the slide bar 656. An oppositeend 667 of the pawl 668 may be pressed to disengage the tip 669 from theteeth 658. In the illustrated embodiment, the tip 669 is configured suchthat it may ratchet along the teeth 658 when the first and second tubes652, 662 are moved toward one another, but remains engaged with theteeth 658 and prevents separation when a force is applied to separatethe first and second tubes 652, 662. With the tubes 652, 662 positionedon the respective sleeves 602, the first and second bodies 654, 664 maybe moved toward one another to compress the sleeves 602, and thereby theelongate members 30, toward one another. The ratchet design of the pawltip 669 maintains the compressive force.

With the hook members 390 maintained in a desired position andorientation, an awl 520 or the like is extended into the surgicalopening and through the openings 397 of the hook members 390, asillustrated in FIGS. 38-39. The awl 520 creates a path through varioustissue, including ligaments and bone, for the connector member 180 to beinserted. For example, as illustrated in FIG. 27, in the finalconstruct, the connector member 180 passes through a spinous process ofa vertebra 510.

The awl 520 is removed and the connector member 180 is installed in thehook members 390 using, for example, the rod introduction instrument 530to insert and position the connector member 180 in the hook members 390(shown in FIGS. 40-41). In addition to the path created by the awl 520,the connector member 180 may include a frustoconical end which mayfurther facilitate introduction of the connector member 180 through thevarious tissue including ligaments and bone.

Once the connector member 180 is properly positioned in the hook members390, fasteners 92 are installed in the hook members 390, as illustratedin FIGS. 42 and 43. Each fastener 92 is positioned on the tip of aninsertion tool 540 and is then passed through an inner channel of theimplant head inserter 400 so as to deliver the fastener 92 to the hookmember 390 and install the fastener 92 into the hook member 390. Oncethe fasteners 92 are installed, the insertion tools 540, the compressorassembly 650, the sleeves 602 and the implant head inserters 400 may allbe removed. The fasteners 92 secure the connector member 180 in the hookmembers 390 and the connector member 180 and hook members 390 to theelongate members 30 such that the final construct illustrated in FIG. 27is achieved.

FIGS. 44-67 show another exemplary method of installing the bonefixation construct 10D, as illustrated in FIG. 27, in bone. In thepresent embodiment, two of couplers 40 have extenders 60 extendingtherefrom similar to the embodiment illustrated in FIG. 1.

Referring to FIG. 44, the bone screws 20, couplers 40, 40A, elongatemembers 30 and caps 50 are installed in a manner similar to thatdescribed above. In accordance with a non-limiting example of aninstallation process, as an initial step, an alignment clip 670 ispositioned on each extender 60. Each alignment clip 670 includes atubular body 672 configured to slidingly engage the respective extender60. The proximal end of each tubular body 672 includes an inwardlyextending shoulder 674 which acts as a stop to maintain the position ofthe tubular body 672 on the extender 60. An alignment tube 676 extendsfrom each tubular body 672. While the illustrated alignment clip 670 hasthe alignment tube 676 in abutting relationship with the tubular body672, the alignment tube 676 may be supported spaced away from thetubular body 672 to achieve a desired position of the hook member 390along the elongate member 30.

Similar to the previous embodiment, each of the hook members 390 isdelivered to the site of the construct through a MIS opening, positionedproximate a predetermined portion of one of the elongate members 30,using an implant head inserter 400. In the present embodiment, eachimplant head inserter 400 is extended through a respective alignmenttube 676, as illustrated in FIG. 45. The implant head inserters 400 aremoved through the alignment tube 676 until the hook member 390 ispositioned proximate to and then hooked onto the elongate member 30 suchthat the elongate member 30 is positioned completely within thereceptacle 395. The alignment tubes 676 ensure that each implant headinserter 400 extends generally perpendicularly to the respectiveelongate member 30 with the hook member 390 in a generally desiredposition.

Referring to FIGS. 46-48, a preliminary locking instrument 680 ispositioned relative to each implant head inserter 400 to temporarilymaintain the position of the hook member 390 and prevent disengagementthereof from the respective elongate member 30. In the presentembodiment, each preliminary locking instrument 680 includes an elongateshaft 681 extending from a proximal end 682 to a distal end 686. In theillustrated embodiment, the proximal end 682 includes a series ofthreads 683 and a fastener head 685 which facilitate securing thepreliminary locking instrument 680 within a respective implant headinserter 400. The distal end 686 of the elongate shaft 681 includes acontact member 687. With the preliminary locking instrument 680 fullypositioned within the implant head inserter 400, the contact member 687engages the elongate member to retain the elongate member 30 within thereceptacle 395. With the hook members 390 and implant head inserters 400locked in position via the preliminary locking instruments 680, thealignment clips 670 may be removed as illustrated in FIG. 49.

Turning to FIGS. 50-52, a compressor assembly 650′ is positioned overthe implant head inserters 400. The compressor assembly 650′ is similarto the compressor assembly 650 and includes a first tube 652 configuredto slide over a first of the inserters 400 and a second tube 662configured to slide over the other inserter 400. In the presentembodiment, the first tube 652 is fixedly connected to a first body654′. The slide bar 656 extends from the first body 654′ such that thefirst tube 652, the first body 654′ and the slide bar 656 define agenerally right angle. The slide bar 658 includes a series of teeth 658defined along one edge thereof and configured to be engaged by a pivotalpawl 668 associated with the second tube 662, as will be described inmore detail hereinafter.

The second tube 662 has a second body 664′ extending therefrom. Thesecond body 664′ includes a slide bar receiving portion 665′ with athrough opening 666 extending therethrough. The slide bar receivingportion 665′ extends toward the first body 654′ parallel to the slidebar 656 which extends through the opening 666. A pawl 668 is pivotallyconnected to the second body 664′ and is biased such that a tip 669 ofthe pawl 668 is normally biased into engagement with the teeth 658 alongthe slide bar 656. An opposite end 667 of the pawl 668 may be pressed todisengage the tip 669 from the teeth 658. In the illustrated embodiment,the tip 669 is configured such that it may ratchet along the teeth 658when the first and second tubes 652, 662 are moved toward one another,but remains engaged with the teeth 658 and prevents separation when aforce is applied to separate the first and second tubes 652, 662. Withthe tubes 652, 662 positioned on the respective inserters 400, the firstand second bodies 654′, 664′ may be moved toward one another to compressthe inserters 400, and thereby the elongate members 30, toward oneanother, as illustrated in FIGS. 51 and 52. The ratchet design of thepawl tip 669 maintains the compressive force. With the hook members 390maintained in a desired position and orientation, the preliminarylocking instruments 680 may be removed as illustrated in FIG. 53.

Turning to FIGS. 53-57, with the compressor assembly 650′ in position,an alignment assembly 690 is positioned on one of the implant headinserters 400. The alignment assembly 690 includes an extending bar 692which includes a clip 694 at one end which engages the implant headinserter 400. A support arm 691 may extend between the extending bar 692and a cap 693 secured into the inserter 400 to further support theextending bar 692. An alignment bar 696 depends from the extending bar692 at junction 697. The junction 697 may be a fixed connection or maybe slightly adjustable to provide alignment adjustment. The free end ofthe alignment bar 696 includes an alignment ring 698 with a throughopening. With the extending bar 692 and alignment bar 696 in position,the through opening of the alignment ring 698 is preferably co-axialwith the openings 397 of the hook members 390. In the illustratedembodiment, a bushing 695 may be positioned in the through opening ofthe alignment ring 698 to define a small opening 699 which is alsoco-axial with the openings 397 of the hook members 390.

Referring to FIGS. 58-59, the opening 699 of the bushing 695 isconfigured to guide a first dilator 700 toward the openings 397 in thehook members 390. The first dilator 700 extends from a proximal end 702to a pointed distal end 704. The first dilator 700 is advanced throughthe opening 699 and partially into the opening 397 of the first hookmember 390. With the first dilator 700 so positioned, an aligned path isestablished between the alignment ring 698 and the opening 397 of thehook member 390.

After the first dilator 700 has been positioned, the bushing 695 isremoved and a second, larger dilator 710 is aligned to be slid over thefirst dilator 700, as illustrated in FIG. 60. The second dilator 710extends from a proximal end 712 to a distal end 714 with a passage 713therethrough. The passage 713 is sized such that the second dilator 710slides over the first dilator 700. The second dilator 710 has an outsidediameter configured to pass through the through opening of the alignmentring 698. The second dilator 710 is advanced until it contacts the firsthook member 390, as illustrated in FIG. 61. With the second dilator 710so positioned, an aligned passage 713 is established between thealignment ring 698 and the opening 397 of the hook member 390. The firstdilator 700 may then be removed, with the aligned passage 713 remaining.

Referring to FIGS. 62-63, an awl 520 or the like is extended into thesurgical opening and through the passage 713. The alignment assembly 690and dilator 710 ensure that the awl 520 is properly directed through theopenings 397 of the hook members 390 and various tissue, includingligaments and bone, of the vertebrae 510. The awl 520 thereby produces aproper path for the connector member 180 to be inserted. For example, asillustrated in FIG. 27, in the final construct, the connector member 180passes through a spinous process of a vertebra 510.

The awl 520 is removed and the connector member 180 is installed in thehook members 390 using, for example, the rod introduction instrument 530to insert and position the connector member 180 in the hook members 390(shown in FIGS. 64-65). In addition to the path created by the awl 520,the connector member 180 may include a frustoconical end which mayfurther facilitate introduction of the connector member 180 through thevarious tissue including ligaments and bone.

Once the connector member 180 is properly positioned in the hook members390, fasteners 92 are installed in the hook members 390, as illustratedin FIGS. 66 and 67. Each fastener 92 is positioned on the tip of aninsertion tool 540 and is then passed through an inner channel of theimplant head inserter 400 so as to deliver the fastener 92 to the hookmember 390 and install the fastener 92 into the hook member 390. Oncethe fasteners 92 are installed, the insertion tools 540, the compressorassembly 650′ and the implant head inserters 400 may all be removed. Thefasteners 92 secure the connector member 180 in the hook members 390 andthe connector member 180 and hook members 390 to the elongate members 30such that the final construct illustrated in FIG. 27 is achieved.

The terms “including,” “comprising,” and variations thereof, as used inthis disclosure, mean “including, but not limited to,” unless expresslyspecified otherwise.

The terms “a,” “an,” and “the,” as used in this disclosure, means “oneor more,” unless expressly specified otherwise.

Devices that are in communication with each other need not be incontinuous communication with each other, unless expressly specifiedotherwise. In addition, devices that are in communication with eachother may communicate directly or indirectly through one or moreintermediaries.

Although process steps, method steps, or the like, may be described in asequential order, such processes and methods be configured to work inalternate orders. In other words, any sequence or order of steps thatmay be described does not necessarily indicate a requirement that thesteps be performed in that order. The steps of the processes or methodsdescribed herein may be performed in any order practical. Further, somesteps may be performed simultaneously.

When a single device or article is described herein, it will be readilyapparent that more than one device or article may be used in place of asingle device or article. Similarly, where more than one device orarticle is described herein, it will be readily apparent that a singledevice or article may be used in place of the more than one device orarticle. The functionality or the features of a device may bealternatively embodied by one or more other devices which are notexplicitly described as having such functionality or features.

While the disclosure has been described in terms of exemplaryembodiments, those skilled in the art will recognize that the disclosurecan be practiced with modifications in the spirit and scope of theappended claims. These examples are merely illustrative and are notmeant to be an exhaustive list of all possible designs, embodiments,applications or modifications of the disclosure.

What is claimed is:
 1. A bone fixation system for implanting in bone,comprising: at least one bone fastener assembly configured to attach tobone; an elongate member configured to attach to each bone fastener; aconnector member configured to engage the elongate member; a hook memberconfigured to engage the elongate member and the connector member,wherein the hook member comprises a hook member body having a firstopening formed between a pair of upwardly extending arms, a receptacle,a hook portion, and a second opening; an elongate implant head inserterhaving a distal tip configured to attach to the hook member; an elongatetemporary locking instrument configured to slide over and around theimplant head inserter and having a distal tip adapted to temporarilyprevent the hook member from disengaging from the elongate member, andwherein the hook member body is configured to taper to the pair ofupwardly extending arms to be received in the implant head inserter. 2.The bone fixation system of claim 1, wherein each bone fastener assemblycomprises: a bone fastener configured to attach to bone; a coupler thatconnects to the bone fastener; and an extender that connects to thecoupler.
 3. The bone fixation system of claim 2, wherein the extendercomprises: a coupling portion that attaches to the coupler; and a bladeportion that attaches to the coupling portion.
 4. The bone fixationsystem of claim 3, wherein coupling portion comprises a threading. 5.The bone fixation system of claim 3, wherein the blade portion comprisesa pair of extender blades.
 6. The bone fixation system of claim 3,wherein the hook member comprises a hook fastener.
 7. The bone fixationsystem of claim 6, wherein the hook fastener secures the connectormember to the hook member.
 8. The bone fixation system of claim 7,wherein the hook fastener secures the hook member and the connectormember to the elongate member.
 9. The bone fixation system of claim 1,wherein the distal tip of the temporary locking instrument includes aplurality of fingers circumferentially spaced from one another.
 10. Thebone fixation system of claim 9, wherein when the temporary lockinginstrument is fully advanced into the implant head inserter, the fingersextend on opposed sides of the elongate member.
 11. A bone fixationsystem for implanting in bone, comprising: a connector member thatcontacts a pair of elongate members; and a hook member configured toengage one of the elongate members and the connector member, wherein thehook member comprises a hook member body having a first opening formedbetween a pair of upwardly extending arms, a receptacle, a hook portion,and a second opening, an elongate implant head inserter having a distaltip configured to attach to the hook member; an elongate temporarylocking instrument configured to slide over and around the implant headinserter and having a distal tip adapted to temporarily prevent the hookmember from disengaging from the elongate member, and wherein the hookmember body is configured to taper to the pair of upwardly extendingarms to be received in the implant head inserter.
 12. The bone fixationsystem of claim 11, further comprising a plurality of bone fastenerassemblies.
 13. The bone fixation system of claim 12, wherein each bonefastener assembly comprises: a bone fastener configured to attach tobone; a coupler that connects to the bone fastener; and an extender thatconnects to the coupler.
 14. The bone fixation system of claim 13,wherein the extender comprises: a coupling portion that attaches to thecoupler; and a blade portion that attaches to the coupling portion. 15.The bone fixation system of claim 14, wherein the coupling portioncomprises a threading.
 16. The bone fixation system of claim 15, whereinthe blade portion comprises a pair of extender blades.
 17. A bonefixation system for implanting in bone, comprising: a plurality of bonefasteners configured to attach to bone; a plurality of couplers thatconnect to the plurality of bone fasteners; a plurality of extendersthat connect to the plurality of couplers; a pair of elongate membersthat attach to the plurality of bone fastener assemblies; a connectormember that contacts the pair of elongate members; and a hook memberconfigured to engage one of the elongate members and the connectormember, wherein the hook member comprises a hook member body having afirst opening formed between a pair of upwardly extending arms, areceptacle, a hook portion, and a second opening, an elongate implanthead inserter having a distal tip configured to attach to the hookmember; an elongate temporary locking instrument configured to slideover and around the implant head inserter and having a distal tipadapted to temporarily prevent the hook member from disengaging from theelongate member, and wherein the hook member body is configured to taperto the pair of upwardly extending arms to be received in the implanthead inserter.
 18. The bone fixation system of claim 17, wherein thehook member comprises a hook fastener.
 19. The bone fixation system ofclaim 18, wherein the hook fastener secures the connector member to thehook member.
 20. The bone fixation system of claim 19, wherein the hookfastener secures the hook member and the connector member to theelongate member.